Systems and Methods for Solar Energy Management

ABSTRACT

An apparatus includes a support member having a proximal end securable to a substantially fixed surface and a distal end opposite the proximal end; a solar energy member mounted to the support member at a location between the proximal and distal ends of the support member, where the solar energy member includes a first portion and a second portion arranged such that the support member extends substantially vertically between the two portions and the two portions are rotatable about a first axis to adjust azimuth of the solar energy member and about a second axis to adjust elevation of the solar energy member; and a plurality of cables, where each cable includes a first end secured to the distal end of the support member and a second end secured to a substantially fixed position, where the cables are configured to resist a wind load acting on the apparatus.

CLAIM OF PRIORITY

This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/444,497 filed on Feb. 18, 2011, entitled “SYSTEMS AND METHODS FOR SOLAR ENERGY MANAGEMENT,” the entire contents of which are hereby incorporated by reference.

TECHNICAL BACKGROUND

This disclosure relates to systems and methods for solar energy management.

BACKGROUND

Solar energy management, collection, and use can often help alleviate energy problems around the world. In particular, solar energy systems such as photovoltaic (“PV”) systems, which generate electrical energy from solar energy can reduce dependence on fossil fuels or other power generation techniques. Additionally, solar energy may be used to generate heat that can subsequently be used in power generation systems. In some cases, solar energy collection systems may include multiple heliostats that reflect solar energy to a receiver. The receiver may then focus the reflected solar energy for a variety of uses. In some instances, heliostats are tracking mirrors, which reflect and focus sunlight onto a distant target, such as the receiver.

For optimal operation, heliostats move precisely and maintain a precise aiming angle, even when acted upon by external forces. For instance, it may be desirable to maintain an angle of a beam of sunlight reflected by the heliostat to within +/−1 milliradian. Substantial wind forces on a planar object, such as a heliostat, may apply forces and torques which tend to knock the beam off-target. One source of aiming errors of heliostats is the mechanical bending of a supporting structure under wind loads. Heliostats that are mounted on top of rigid posts firmly anchored to the ground, thereby effectively acting as a cantilevered beam, are subject to wind forces acting to “push over” the posts. To resist bending, the post must be very rigid and anchored securely into the ground. Often, the material and installation cost of rigid posts and secure foundations can be prohibitive to installation of a system of heliostats.

SUMMARY

In one general embodiment, an apparatus includes: a support member having a proximal end securable to a substantially fixed surface and a distal end opposite the proximal end; a solar energy member mounted to the support member at a location between the proximal and distal ends of the support member, where the solar energy member includes a first portion and a second portion arranged such that the support member extends substantially vertically between the two portions and the two portions are rotatable about a first axis to adjust azimuth of the solar energy member and about a second axis to adjust elevation of the solar energy member; and a plurality of cables, where each cable includes a first end secured to the distal end of the support member and a second end secured to a substantially fixed position, where the cables are configured to resist a wind load acting on the apparatus.

In another general embodiment, a method for managing a solar energy system includes: mounting a proximal end of a substantially vertical support member to a substantially fixed surface, the support member having a distal end opposite the proximal end; mounting a solar energy member to the support member at a location between the proximal and distal ends of the support member, the solar energy member including a first portion and a second portion arranged such that the support member extends between the first and second portions and the first and second portions are rotatable about a first axis to adjust azimuth of the solar energy member and about a second axis to adjust elevation of the solar energy member; securing a plurality of cables to the support member adjacent the distal end of the support member at respective first ends of the cables; and securing the plurality of cables to one or more substantially fixed positions at respective second ends of the cables, where the cables are configured to resist a wind load acting on the solar energy system.

In another general embodiment, a solar energy system includes: a first plurality of heliostats arranged in a first row; and a second plurality of heliostats arranged in a second row that is substantially parallel to the first row. At least one of the first plurality of heliostats and at least one of the second plurality of heliostats include: a vertical support member having a proximal end secured to a base supported by a terranean surface and a distal end opposite the proximal end; a mirror member mounted to the vertical support member at a location between the proximal and distal ends of the vertical support member, where the mirror member includes a first portion and a second portion arranged such that the vertical support member extends vertically between the two portions and the two portions are rotatable about a first axis to adjust azimuth of the solar energy member and about a second axis to adjust elevation of the solar energy member; and a plurality of cables, each cable including a first end secured to the distal end of the vertical support member and a securable second end opposite the first end, and where the cables are configured to resist a wind load acting on the heliostat.

In one or more aspects of one or more general embodiments, the solar energy member may include a reflective surface configured to reflect solar rays incident on the reflective surface toward a solar energy receiver.

In one or more aspects of one or more general embodiments, the solar energy member may be configured to rotate about the first axis to adjust azimuth of the solar energy member and about the second axis to adjust elevation of the solar energy member without touching the plurality of cables such the solar rays incident on the reflective surface are reflected toward the solar energy receiver.

In one or more aspects of one or more general embodiments, the solar energy member may be a solar panel including at least one photovoltaic cell.

In one or more aspects of one or more general embodiments, the plurality of cables may include three cables, where the three cables are secured to the distal end of the support member at respective first ends of the cables and secured to distinct substantially fixed positions at respective second ends of the cables opposite the respective first ends.

In one or more aspects of one or more general embodiments, the location between the proximal and distal ends of the support member may be at approximately a midpoint of the support member between the distal end of the support member and the substantially fixed surface.

In one or more aspects of one or more general embodiments, the location may include a position on the support member where angular deflection of the support member due to the wind load on the apparatus is minimized as a function of lateral deflection of the support member due to the wind load.

In one or more aspects of one or more general embodiments, the first and second portions of the solar energy member may be substantially equal in size.

In one or more aspects of one or more general embodiments, the support member may be a wooden post.

In one or more aspects of one or more general embodiments, the substantially fixed surface may be a footer including one of the following: a post hole formed in a terranean surface and configured to receipt the support member; a concrete mass including an aperture configured to receive the support member; or a plastic boot securable to the terranean surface and configured to receive the support member.

In one or more aspects of one or more general embodiments, the support member may include a first support member, and the substantially fixed position to which the second end of at least one cable is secured may include a footer of a second support member, the second support member having a proximal end securable to the footer and a distal end opposite the proximal end, the second support member configured to support a second solar energy member mounted to the support member at a location between the proximal and distal ends of the second support member.

In one or more aspects of one or more general embodiments, the solar power member may include an aspect ratio of approximately 4:1.

In one or more aspects of one or more general embodiments, securing the plurality of cables to one or more substantially fixed positions at respective second ends of the cables may include securing each of the cables to a distinct location on a terranean surface at the respective second end of the cable.

In one or more aspects of one or more general embodiments, securing the plurality of cables to one or more substantially fixed positions at respective second ends of the cables may include securing each of the cables to another support member distinct from the support member at the respective second end of the cable.

One or more aspects of one or more general embodiments may further include rotating the solar energy member about the first axis to adjust azimuth of the solar energy member without touching the plurality of cables such that the solar rays incident on a reflective surface of the solar energy member are reflected toward a solar energy receiver; and rotating the solar energy support member about the second axis to adjust elevation of the solar energy member without touching the plurality of cables such that the solar rays incident on a reflective surface of the solar energy member are reflected toward a solar energy receiver.

In one or more aspects of one or more general embodiments, at least some of the second ends of cables of heliostats in the first row may be secured to bases of heliostats in the second row and at least some of the second ends of cables of heliostats in the second row are secured to bases of heliostats in the first row.

One or more aspects of one or more general embodiments may include a third plurality of heliostats arranged in a third row positioned between the first and second rows.

One or more aspects of one or more general embodiments may include a fourth plurality of heliostats arranged in a fourth row positioned such that one of the first or second rows are between the third and fourth rows. At least one of the fourth plurality of heliostats may include: a vertical support member having a proximal end secured to a base supportable by the terranean surface and a distal end opposite the proximal end; a mirror member mounted to the vertical support member at a location between the proximal and distal ends of the vertical support member, where the mirror member includes a first portion and a second portion arranged such that the vertical support member extends vertically between the two portions and the two portions are rotatable about the vertical support member; and a plurality of cables, each cable including a first end secured to the distal end of the vertical support member and a second end opposite the first end. At least some of the second ends of cables of heliostats in the fourth row are secured to bases of heliostats in the third row and at least some of the second ends of cables of heliostats in the third row are secured to bases of heliostats in the fourth row.

In one or more aspects of one or more general embodiments, cables secured to the distal ends of vertical support members of particular heliostats in the first plurality of heliostats at respective first ends of the cables may be secured to the distal ends of vertical support members of particular heliostats in the second plurality of heliostats at respective second ends of the cables.

In one or more aspects of one or more general embodiments, the first plurality of heliostats may include a first heliostat positioned at an end of the first row such that a first cable secured to a distal end of the first heliostat at the first end of the cable is also secured to the terranean surface at the second end of the cable, and a second cable secured to the distal end of the first heliostat at the first end of the second cable is also secured to a distal end of a second heliostat.

In one or more aspects of one or more general embodiments, the second heliostat may be one of the second plurality of heliostats arranged in the second row. The second heliostat may be one of the first plurality of heliostats arranged in the first row.

Various implementations of a solar energy system according to the present disclosure may include one or more of the following features and/or advantages. For example, the solar energy system may provide a relatively inexpensive structure for mounting solar energy members, such as heliostats, while maintaining sufficient rigidity for operation of the members. For instance, the system may maintain a heliostat mirror at an optimal position for reflecting sunlight towards a solar receiver even when subject to a wind load producing a bending moment on a supporting structure of the member. The system may also use relatively inexpensive tension cables to secure a heliostat support structure to a fixed surface when the structure is subject to a wind load that produces a bending moment of the structure. For instance, inexpensive tension-cables may be used in place of expensive structural foundations and beams to resist bending of a heliostat support structure. The system may also utilize a symmetric geometry to minimize angular deflections of a heliostat mirror (or other solar energy member) due to wind loads, thereby allowing the use of inexpensive, compliant materials that can flex significantly without adverse effect on the operation of the system. Further, the system may utilize inexpensive footings placed with minimal ground preparation and on-site installation cost as compared to expensive structural foundations of a heliostat support structure.

These general and specific aspects may be implemented using a device, system or method, or any combinations of devices, systems, or methods. The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 illustrates an example embodiment of a solar energy system;

FIG. 2 illustrates an example embodiment of a solar energy array of multiple heliostats;

FIG. 3 illustrates another example embodiment of a solar energy array of multiple heliostats;

FIG. 4 illustrates an example embodiment of a solar energy array of multiple solar energy assemblies; and

FIG. 5 illustrates an example method for managing a solar energy system.

DETAILED DESCRIPTION

The present disclosure describes embodiments of a solar energy assembly and solar energy systems with an array (or multiple arrays) of solar energy assemblies. In one embodiment, a solar energy assembly according to the present disclosure may include a support structure with a substantially vertical structural member secured to a terranean surface by a footing structure. A solar energy member, such as a heliostat mirror or PV cell, may be mounted near a midpoint of the structural member for rotational and pivotal movement about orthogonal axes intersecting the midpoint of the structural member. Multiple cables are secured at first ends of the cables to a top portion of the structural member and at second ends of the cables to anchors. In some aspects, the support structure and cables may limit angular deflection of the solar energy member during lateral deflection of the structural member due to, for example, a wind load on the solar energy assembly.

FIG. 1 illustrates an example embodiment of a solar energy system 100. Solar energy system 100, as illustrated, may collect or reflect solar energy from a remote source (e.g., the Sun or other solar energy source) while rotatably tracking the source under varying environmental conditions. For example, in some embodiments, the solar energy system 100 may be a heliostat that tracks (e.g., rotates along an azimuth and/or pivots through an elevation) the Sun in order to receive and reflect solar energy from the Sun to a solar energy collector located remote from the heliostat. In some instances, the solar energy system 100 may be one of many systems 100 installed within a field or array that operate in concert to collect and/or reflect solar energy provided by the remote source.

In some instances, the solar energy system 100 may stably operate through a variety of environmental conditions, such as wind, rain, snow, hail, and other conditions. As illustrated, for example, the solar energy system 100 may be subject to a wind force (F_(w)) acting on one or more components of the system 100. The illustrated solar energy system 100 includes a support member 110 with a distal end 115 and proximal end 120, a solar energy member 135, and one or more cables 145. As illustrated, the solar energy system 100 is secured to or supported by a terranean surface 105.

The support member 110, as illustrated, is substantially vertical in orientation and mounted orthogonal to the terranean surface 105 in a footer 125. The support member 110, in some embodiments, may be a wooden post, such as a cylindrical wooden post treated for exposure to varying environmental conditions (e.g., moisture, heat, and otherwise). Alternatively, the support member 110 may be any suitable material, such as stainless steel, painted ferrous steel, formed concrete, or otherwise, that may be secured in a substantially vertical position and support the solar energy member 135.

The illustrated support member 110 is secured and/or attached to the footer 125 at the proximal end 120 of the member 110. In some embodiments, the footer 125 may be a concrete foundation installed to a particular depth below the terranean surface 105, thereby forming a cantilevered beam with the support member 110.

Alternatively, however, the footer 125 may be supported by the terranean surface 105 without being installed or anchored below the surface 105. The footer 125 may be a structure that can support the member 110 in a substantially vertical position under the weight of the solar energy member 135 (both static weight and dynamic weight during movement of the solar energy member 135). For example, the footer 125 can be a block or mass of concrete or other material (e.g., glass reinforced plastic) that includes an aperture or other recess for installation of the support member 110 therein. Further, in some embodiments, the footer 125 may not be installed to support the member 110 and instead, the support member 110 may be inserted into a post hole formed in the terranean surface 105. In some instances, a footer 125 that is supported by the surface 105 or installation of the support member 110 without the footer 125 may be significantly more efficient (e.g., in relative costs, installation time, and otherwise) as compared to a foundational structure formed beneath the terranean surface 105.

As illustrated, the footer 125 may not need to resist any overturning moments in the support member 110, in contrast to, for example, a foundational structure formed beneath the terranean surface 105 for anchoring the support member 110. For instance, the footer 125 may only need to resist and/or substantially prevent lateral “skidding” of the footer 125 and support member 110 across the terranean surface 105. Further, the footer 125 may prevent or substantially prevent the support member 110 from sinking beneath the terranean surface 105.

Changes in azimuth of the solar energy member 135 refers to rotation of the solar energy member 135 about a vertical axis, i.e., rotation in the direction shown by arrow 118 about the azimuthal axis 117. Changes in elevation of the solar energy member 135 refers to changes in the angle between the direction the solar energy member 135 is pointing and a local horizontal plane, i.e., changes in the up-down angle. As shown in FIG. 1, rotation of the solar energy member 135 in the direction shown by the arrow 138 about the elevational axis 137 changes the elevation of the solar energy member 135. The solar energy member 135 is mounted to the support member 110 such that rotation about the azimuthal axis 117 (in this implementation, coincident with a centerline of the support member 110) and rotation (i.e., pivotal movement) about the elevational axis 137 within desired ranges to account for tracking the Sun throughout the course of day and throughout the days of a year are permitted without interference by the support member 110 or the cables 145. In the illustrated embodiment, the solar energy member 135 may be a heliostat mirror, which receives and reflects solar energy incident on a surface of the member 135 towards a remote location, such as a solar energy receiver. Alternatively, however, the solar energy member 135 may be another solar energy device, such as a PV. In any event, the solar energy member 135, typically, is substantially planar and includes at least one surface that receives and reflects (i.e., a heliostat mirror) or receives and absorbs (i.e., a PV) solar energy.

While not shown in FIG. 1, one or more actuators (e.g., motors or other actuator assemblies) may be coupled between the support member 110 and solar energy member 135 and facilitate such rotational and pivotal movement of the solar energy member 135 about the azimuthal axis 117 and elevational axis 137, respectively. In some embodiments, for example, the actuators may be controlled (e.g., locally at the solar energy system 100 or remotely) to track the Sun as it moves across the sky.

In the illustrated embodiment, the solar energy member 135 is split into a first portion 140 a and a second portion 140 b, with the support member 110 extending vertically (e.g., substantially or otherwise) between the two portions 140 a and 140 b. In some embodiments, the first and second portions 140 a and 140 b may be substantially equal in surface area. Alternatively, the first and second portions 140 a and 140 b may differ in size, depending on, for example, the solar energy application. In some embodiments, the first portion 140 a and the second portion 140 b are joined or integral to either other and include an elongated opening in between the two portions through which the support member 110 passes, to allow for changes in azimuth and elevation of the solar energy member 135 (i.e., rotation about the azimuthal axis 117 and elevational axis 137). As illustrated, the first and second portions 140 a and 140 b are mounted near a position of the support member 110 that is between the distal end 115 and proximal end 120 of the member 110.

One or more cables 145 may be secured to the distal end 115 of the support member 110 (e.g., an end most location of the support member 110 or portion of the support member 110 near and/or including the endmost location of the support member 110) at one end of the cable, and may also be secured to the terranean surface 105 at corresponding anchors 150. The anchors 150 may be, for example, helical ground screws, stakes, or heavy concrete blocks (e.g., with embedded eye-hooks). As described below, the anchors 150 may be footers of neighboring support members of other solar energy systems 100 arranged in an array of solar energy systems 100. In any event, the anchors 150 may secure the cables 145 to or at the terranean surface 105 with sufficient tension such that the cables 145 are taut.

The cables 145 may be secured to the distal end 115 of the support member 110 through a number of techniques. For example, the cables 145 can be secured to the distal end 115 of the support member 110 using eye-hooks screwed-in to the member 110 (e.g., screwed into a wooden portion of the member 110), simple wrapping, or other mechanical attachments. In some embodiments, the support member 110 may be treated wood covered with a stamped-steel cap at the distal end 115. The cap may include formed loops through which the cables 145 can be attached.

In the illustrated embodiment of the solar energy system 110, three cables 145 are each secured to the distal end 115 of the support member 110 as well as corresponding anchors 150. The three cables 145 are arranged at approximately 120 degree intervals around the support member 110. Alternatively, other arrangements of the cables 145 may include more cables and/or cables secured around the support member 110 at different locations (e.g., in 60 degree intervals, 90 degree intervals, or otherwise). In any event, in the illustrated embodiment, the cables 145 are secured to the support member 110 and anchors 150 so as to allow free rotation and pivotal movement of the solar energy member 135 about the support member 110 without contact with the cables 145. Further, in embodiments where the solar energy system 100 is arranged in an array, or tessellation, of multiple solar energy systems, the cables 145 may be secured to the support member 110 and the anchors 150 so as to be free of contact with any other solar energy members of neighboring and/or adjacent solar energy systems.

As illustrated, the solar energy system 100 may be subject to a wind load, F_(w), which may act on the support member 110 and/or solar energy member 135. F_(w) may act on the solar energy system 100 to cause a bending moment in the support member 110. Typically, this bending moment in the support member 110 may adversely affect the position of the solar energy member 135 mounted on the support member 110. For example, the solar energy member 135 may be precisely positioned (e.g., rotated and/or pivoted) so as to receive solar energy from the Sun at specific pointing angles in order to, for instance, reflect the solar energy to a fairly precise remote location. Adverse movement of the solar energy member 135 (e.g., angular deflection) due to, for example, the wind load, may also adversely affect the operation of the solar energy system 100.

In the illustrated embodiment, however, the positioning of the solar energy member 135 (in split form with first and second portions 140 a and 140 b) vertically in the support member 110 and anchoring of the support member 110 with the cables 145 may render the solar energy member 135 substantially insensitive to bending of the support member 110. For example, as illustrated, the support member 110 is substantially fixed at the distal end 115 and proximal end 120 with respect to the terranean surface 105: the proximal end 120 is secured by the footer 125, and the distal end 115 by the cables 145. When the wind load acts on the solar energy member 135 (which acts as a “sail”), F_(w) is transmitted from the solar energy member 135 to the support member 110 and more specifically, to the point of the support member 110 at which the solar energy member 135 is mounted. The support member 110 may thus “bow” at this point but the top and proximal ends 115 and 120 are substantially fixed in space (and thus may not experience translational movement) due to the cables 135 and the footer 125. Thus, an angle of the support member 110 relative to the terranean surface 105 at the point at which the solar energy member 135 is mounted may remain substantially constant under wind loads. The pointing angle of the solar energy member 135 may, therefore, remain substantially constant under wind loads.

In some embodiments, the point, or location, of the support member 110 at which the solar energy member 135 is mounted is at or near a midpoint location between the distal end 115 and the proximal end 120. In some embodiment, the mounting point of the solar energy member 135 is selected at a location of the support member 110 at which angular deflection of the support member 110 due to a dynamic load, e.g., F_(w), is minimized as a function of lateral deflection of the support member 110 due to the wind load (e.g., F_(w)) on the support member 110. Further, in some embodiments, the mounting point at which angular deflection of the support member 110 is minimized may be coincident with a location at or near the midpoint of the support member 110 between the top and proximal ends 115 and 120, respectively. In embodiments in which the solar energy member 135 is a heliostat mirror, the mirror may operate successfully even when subject to lateral translation as long as change to the pointing angle of the mirror (i.e., angle of the mirror toward a remote location) is minimized. For example, for successful operation, the heliostat mirror may aim at an approximately 3 meter target about 100 meters from the mirror. Even small angular deflections (˜1 milliradian) may cause the mirror to miss the target with reflected solar energy. But if the angular deflection is minimized, lateral deflection of the heliostat mirror (e.g., up to several centimeters) may not adversely affect operation (i.e., targeting) of the heliostat mirror.

FIG. 2 illustrates an example embodiment of a solar energy array 200 of multiple heliostats 205 a through 205 e. One or more of the heliostats 205 a through 205 e may be substantially similar to the solar energy system 100 illustrated in FIG. 1. In some embodiments, the array 200 may be installed in an open-space environment along with a solar energy receiver (not shown here) in order to capture solar energy for various uses. More specifically, solar energy may be received and reflected by the heliostats 205 a through 205 e towards the solar energy receiver as the heliostats 205 a through 205 e track the movement of the Sun through the daytime sky. As described above, each of the heliostats 205 a through 205 e may retain one or more mirrors at specific pointing angles even when subject to dynamic loads (e.g., wind loads) by securing a support member to a terranean surface with multiple cables.

In the illustrated embodiment of system 200, two rows 210 and 215 of heliostats 205 are shown. Of course, system 200 may illustrate just a portion of a larger array of heliostats 205. As illustrated, heliostats 205 a through 205 c in row 210 are at least partially secured at anchors 220 of row 215. The anchors 220, in some embodiments, may be footers of support members of the heliostats 205 d and 205 e in row 215. For instance, at least one cable secured to a distal end of heliostat 205 a, 205 b, and 205 c may also be secured to a footer of a heliostat (e.g., heliostat 205 d and 205 e) in row 215. Thus, footers of heliostats in one row of heliostats (e.g., row 215) may be utilized as anchors 220 for cables of heliostats in an adjacent or neighboring row of heliostats (e.g., row 210).

As illustrated, heliostats 205 d through 205 e in row 215 may also be at least partially secured at anchors 220 of row 210. The anchors 220, in some embodiments, may be footers of support members of the heliostats 205 a through 205 c in row 210. For instance, at least one cable secured to a distal end of heliostats 205 d and 205 e may also be secured to a footer of a heliostat (e.g., heliostat 205 a through 205 c) in row 210. Further, each of the heliostats 205 in rows 210 and 215 may be secured such that mirrors of the heliostats 205 may rotate and/or pivot (e.g., for azimuthal and/or elevational adjustment) without contacting any cables in the system 200.

One or more of the heliostats 205 in the solar energy array 200 may surround and point to a solar energy receiver 225. The solar energy receiver 225, typically, receives the Sun's solar energy 230 reflected from heliostat mirrors of the heliostats 205 and, in some cases, transfers the received solar energy to one or more processes (e.g., heating, power generation, and otherwise). In some embodiments, the solar energy receiver 225 may include a target 235 to which the solar energy 230 is directed by the heliostats 205. While the heliostats 205 and solar energy receiver 225 are at substantially fixed locations, the Sun's position in the sky changes during the day. Thus, the heliostats 205 may rotate to track the location of the Sun (i.e., azimuthal tracking) while also tracking the Sun's position in the sky above the horizon (i.e., elevational tracking) in order to keep the solar energy 230 aimed at the target 235. The mirrors of the heliostats 205 may, therefore, be kept perpendicular to a bisector of an angle between the direction of the Sun and the target 235 as seen from the mirrors of the heliostats 205.

FIG. 3 illustrates another example embodiment of a solar energy array 300 of a plurality of heliostats 310 in rows 305 of heliostats. One or more of the heliostats 310 may be substantially similar to the solar energy system 100 illustrated in FIG. 1. In some embodiments, the array 300 may be installed in an open-space environment along with a solar energy receiver (not shown here) in order to capture solar energy for various uses. More specifically, solar energy may be received and reflected by the heliostats 310 towards the solar energy receiver as the heliostats 310 track the movement of the Sun through the daytime sky. As described above, each of the heliostats 310 may retain one or more mirrors at specific pointing angles even when subject to dynamic loads (e.g., wind loads) by securing a support member to a terranean surface with multiple cables.

As illustrated, FIG. 3 shows an array or tessellation of a heliostat field in which cables securing support members of the heliostats 310 to a terranean surface avoid interference (e.g., contact) with other cables and mirrors of the heliostats. For example, system 300 may include heliostats 310 with roughly 4:1 width-to-height aspect ratios. In some cases, therefore, each heliostat 310 may include a swept volume of rotation 315 that is approximately cylindrical. System 300 may also illustrate a heliostat array with hexagonal packing, where each heliostat 310 is surrounded by six neighbors whose corresponding swept volumes of rotation 315 just barely avoid interference with swept rotational volumes 315 of adjacent heliostats 310.

As illustrated in system 300, a support member of each heliostat 310 may be secured by three supporting cables, which may provide sufficient stability to resist lateral forces (e.g., wind forces) from any direction. The three cables, as shown, may be secured to the footings of three second-nearest neighbor heliostats, with 120-degree angular spacing between each of the three cables. Thus, a cable angle between the top of a first support member and a footer of a support member of a second-nearest heliostat 310 may provide sufficient clear volume around the support member to allow free rotation of a heliostat mirror around the support member.

FIG. 4 illustrates an example embodiment of a solar energy array 400 of a plurality of solar energy assemblies 420 and 425. Array 400 may illustrate all or a portion of a larger array or tessellation of solar energy assemblies 420 and 425 that may receive and reflect and/or collect solar energy from the Sun 305 (or other solar energy source). For example, the solar energy assemblies 420 and 425 may be heliostats that receive and reflect solar energy from the Sun 405 toward a remote solar receiver. The solar energy assemblies 420 and 425 may, alternatively, be PV assemblies that receive and absorb solar energy from the Sun 405. At least some of the solar energy assemblies 420 and 425 may be substantially similar to the solar energy system 100 as illustrated in FIG. 1.

As illustrated, array 400 includes rows 415 a and 415 b of solar energy assemblies. Row 415 a includes solar energy assemblies 425 a through 425 d. Row 415 b includes solar energy assemblies 420 a through 420 d. As illustrated, each of the solar energy assemblies 420 and 425 include multiple cables secured to corresponding distal ends of adjacent assemblies, as well as secured to other substantially fixed locations. For example, as illustrated, cables 435 are secured to distal ends of solar energy assemblies in adjacent rows. As shown, cables 435 are secured between adjacent solar energy assemblies 425 a and 420 a (as well as 425 b and 420 b, and 425 c and 420 c) in rows 415 a and 415 b, respectively. Cables 430 are secured between distal ends of solar energy assemblies in the same row. For instance, respective cables 430 are secured between respective distal ends of solar energy assemblies 420 a and 420 b, 420 b and 420 c, and 420 c and 420 d, in row 415 b. Further, respective cables 430 are secured between respective distal ends of solar energy assemblies 425 a and 425 b, 425 b and 425 c, and 425 c and 425 d, in row 415 a.

As illustrated, cables 440 are secured to distal ends of certain solar energy assemblies, as well as a terranean surface 410. For example, cables 440 are secured to distal ends of solar energy assemblies 420 d and 425 d, which are end-most assemblies in rows 415 b and 415 a, respectively. Further, cables 440 may be secured to distal ends of solar energy assemblies 420 a through 420 d, which are end-most assemblies of rows 415 c through 415 f, respectively. Thus, cables 440, in some embodiments, may secure solar energy assemblies arranged at an end of a row of solar energy assemblies to the terranean surface 410.

In some embodiments, cables 440 may have a higher tensile strength as compared to cables 430 and cables 435. Thus, cables 440 may be larger (e.g., in diameter) or may be made from a different material as compared to cables 430 and 435. For example, a cable 440 may be secured to the solar energy assembly 420 d at the end of row 415 b so as to limit angular deflection of the solar energy assemblies 420 a through 420 d (and possibly more assemblies in the row 415 b not shown in FIG. 4) when the solar energy assemblies in the row 415 b are subjected to a wind load. As the wind load may act on each solar energy assembly within the row 415 b, the cable 440 may be sized and/or designed to minimize lateral deflection of the solar energy assemblies within the row 415 b based on the sum of the wind loads acting on solar energy assemblies 420 a through 420 d.

FIG. 5 illustrates an example method 500 of managing a solar energy system, such as, for example, the solar energy system 100 shown in FIG. 1 or other solar energy system. At step 502, a support member may be mounted to a substantially fixed surface at a proximal end of the member. For example, the support member may be a substantially vertically mounted wooden post secured at the proximal end within a footer or foundational structure in a terranean surface. The footer may be a cast structure supportable by the terranean surface. At step 504, a solar energy member is mounted to the support member. In some aspects, the solar energy member may be split into first and second portions such that the support member extends vertically between the first and second portions. Further, the solar energy member may be mounted at a location between the proximal end of the support member and a distal end opposite the proximal end. Multiple cables may be secured to the support member at the distal end of the member at step 506. For example, in some embodiments, three or more cables may be secured to one (or multiple) eye-hooks embedded in the support member.

At step 508, one or more of the multiple cables may be secured to the terranean surface at ends opposite the cable ends secured to the support member. For instance, each cable may be anchored (e.g., with spikes insertable into the surface, moveable structures supported by the surface, and otherwise) to the terranean surface at substantially symmetric radially positions around the support member. For example, in the case of three cables, each cable may be deployed at 120 degree increments around the support member and anchored to the surface.

In addition to, or alternative to, step 508, one or more of the multiple cables may be secured to adjacent support members at step 510. For example, the solar energy system may be one of many solar energy systems configured in an array or tessellation of systems about a common solar energy receiver (such as the solar energy receiver 225 shown in FIG. 2). One or more cables may thus be secured at ends opposite the cable ends secured to the support member to adjacent (or even next to adjacent) support members. In some embodiments, the cables may be secured to adjacent (or next to adjacent) support members at respective footers of the support members. Alternatively, the cables may be secured to adjacent (or next to adjacent) support members at respective distal ends of the support members.

At step 512, the solar energy member is rotated about an azimuthal axis coincident with a vertical axis of the support member. At step 514, the solar energy member is rotated about an elevational axis orthogonal to the vertical axis of the support member. Rotation of the solar energy member about both the azimuthal and elevational axes is accomplished without contact between the solar energy member and the cables secured to the support member. As noted above, rotation of the solar energy member about the elevational axis changes the elevation of the solar energy member. The solar energy member may be mounted to the support member such that rotation about the azimuthal axis and rotation (i.e., pivotal movement) about the elevational axis within desired ranges to account for tracking the Sun throughout the course of day and throughout the days of a year are permitted without interference by the support member or the cables.

A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made. For example, while some embodiments have been described and/or illustrated in terms of heliostats, other solar energy members, such as PV cells, may also be utilized in accordance with the present disclosure. Further, method 500 may include less steps than those illustrated or more steps than those illustrated. In addition, the illustrated steps of method 500 may be performed in the order illustrated or in different orders than that illustrated. For example, in some implementations, the solar energy member can be mounted on the support member before the support member is mounted to a fixed surface. Similarly, in some implementations, the multiple cables can be attached to the distal end of the support member before the support member is mounted to the fixed surface. Other variations in the order of steps is also possible. Accordingly, other implementations are within the scope of the following claims. 

1. A solar energy system, comprising: a first plurality of heliostats arranged in a first row; and a second plurality of heliostats arranged in a second row that is substantially parallel to the first row, wherein at least one of the first plurality of heliostats and at least one of the second plurality of heliostats comprise: a vertical support member having a proximal end secured to a base supported by a terranean surface and a distal end opposite the proximal end; a mirror member mounted to the vertical support member at a location between the proximal and distal ends of the vertical support member, wherein the mirror member includes a first portion and a second portion arranged such that the vertical support member extends vertically between the two portions and the two portions are rotatable about a first axis to adjust azimuth of the solar energy member and about a second axis to adjust elevation of the solar energy member; and a plurality of cables, each cable comprising a first end secured to the distal end of the vertical support member and a securable second end opposite the first end, wherein the cables are configured to resist a wind load acting on the heliostat.
 2. The system of claim 1, wherein at least some of the second ends of cables of heliostats in the first row are secured to bases of heliostats in the second row and at least some of the second ends of cables of heliostats in the second row are secured to bases of heliostats in the first row.
 3. The system of claim 1, further comprising: a third plurality of heliostats arranged in a third row positioned between the first and second rows.
 4. The system of claim 3, further comprising: a fourth plurality of heliostats arranged in a fourth row positioned such that one of the first or second rows are between the third and fourth rows, wherein at least one of the fourth plurality of heliostats comprise: a vertical support member having a proximal end secured to a base supportable by the terranean surface and a distal end opposite the proximal end; a mirror member mounted to the vertical support member at a location between the proximal and distal ends of the vertical support member, wherein the mirror member includes a first portion and a second portion arranged such that the vertical support member extends vertically between the two portions and the two portions are rotatable about the vertical support member; and a plurality of cables, each cable comprising a first end secured to the distal end of the vertical support member and a second end opposite the first end, wherein at least some of the second ends of cables of heliostats in the fourth row are secured to bases of heliostats in the third row and at least some of the second ends of cables of heliostats in the third row are secured to bases of heliostats in the fourth row.
 5. The system of claim 1, wherein cables secured to the distal ends of vertical support members of particular heliostats in the first plurality of heliostats at respective first ends of the cables are secured to the distal ends of vertical support members of particular heliostats in the second plurality of heliostats at respective second ends of the cables.
 6. The system of claim 1, wherein the first plurality of heliostats comprises a first heliostat positioned at an end of the first row such that a first cable secured to a distal end of the first heliostat at the first end of the cable is also secured to the terranean surface at the second end of the cable, and a second cable secured to the distal end of the first heliostat at the first end of the second cable is also secured to a distal end of a second heliostat.
 7. The system of claim 6, wherein the second heliostat is one of the second plurality of heliostats arranged in the second row.
 8. The system of claim 6, wherein the second heliostat is one of the first plurality of heliostats arranged in the first row.
 9. An apparatus comprising: a support member having a proximal end securable to a substantially fixed surface and a distal end opposite the proximal end; a solar energy member mounted to the support member at a location between the proximal and distal ends of the support member, wherein the solar energy member includes a first portion and a second portion arranged such that the support member extends substantially vertically between the two portions and the two portions are rotatable about a first axis to adjust azimuth of the solar energy member and about a second axis to adjust elevation of the solar energy member; and a plurality of cables, each cable comprising a first end secured to the distal end of the support member and a second end secured to a substantially fixed position, wherein the cables are configured to resist a wind load acting on the apparatus.
 10. The apparatus of claim 9, wherein the solar energy member comprises a reflective surface configured to reflect solar rays incident on the reflective surface toward a solar energy receiver.
 11. The apparatus of claim 10, wherein the solar energy member is configured to rotate about the first axis to adjust azimuth of the solar energy member and about the second axis to adjust elevation of the solar energy member without touching the plurality of cables such the solar rays incident on the reflective surface are reflected toward the solar energy receiver.
 12. The apparatus of claim 9, wherein the solar energy member is a solar panel comprising at least one photovoltaic cell.
 13. The apparatus of claim 9, the plurality of cables comprising three cables, wherein the three cables are secured to the distal end of the support member at respective first ends of the cables and secured to distinct substantially fixed positions at respective second ends of the cables opposite the respective first ends.
 14. The apparatus of claim 9, wherein the location between the proximal and distal ends of the support member is at approximately a midpoint of the support member between the distal end of the support member and the substantially fixed surface.
 15. The apparatus of claim 9, wherein the location comprises a position on the support member where angular deflection of the support member due to the wind load on the apparatus is minimized as a function of lateral deflection of the support member due to the wind load.
 16. The apparatus of claim 9, wherein the first and second portions of the solar energy member are substantially equal in size.
 17. The apparatus of claim 9, wherein the support member comprises a wooden post.
 18. The apparatus of claim 9, wherein the substantially fixed surface is a footer comprising one of the following: a post hole formed in a terranean surface and configured to receipt the support member; a concrete mass including an aperture configured to receive the support member; or a plastic boot securable to the terranean surface and configured to receive the support member.
 19. The apparatus of claim 18, wherein the support member comprises a first support member, and the substantially fixed position to which the second end of at least one cable is secured comprises a footer of a second support member, the second support member having a proximal end securable to the footer and a distal end opposite the proximal end, the second support member configured to support a second solar energy member mounted to the support member at a location between the proximal and distal ends of the second support member.
 20. The apparatus of claim 9, wherein the solar power member comprises an aspect ratio of approximately 4:1.
 21. A method for managing a solar energy system comprising: mounting a proximal end of a substantially vertical support member to a substantially fixed surface, the support member having a distal end opposite the proximal end; mounting a solar energy member to the support member at a location between the proximal and distal ends of the support member, the solar energy member comprising a first portion and a second portion arranged such that the support member extends between the first and second portions and the first and second portions are rotatable about a first axis to adjust azimuth of the solar energy member and about a second axis to adjust elevation of the solar energy member; securing a plurality of cables to the support member adjacent the distal end of the support member at respective first ends of the cables; and securing the plurality of cables to one or more substantially fixed positions at respective second ends of the cables, wherein the cables are configured to resist a wind load acting on the solar energy system.
 22. The method of claim 21, wherein the location comprises a position on the support member where angular deflection of the support member due to a wind load on the support member is minimized as a function of lateral deflection of the support member due to the wind load on the support member.
 23. The method of claim 21, wherein the location is near a midpoint between the distal end of the support member and the substantially fixed surface.
 24. The method of claim 21, wherein securing the plurality of cables to one or more substantially fixed positions at respective second ends of the cables comprises securing each of the cables to a distinct location on a terranean surface at the respective second end of the cable.
 25. The method of claim 21, wherein securing the plurality of cables to one or more substantially fixed positions at respective second ends of the cables comprises securing each of the cables to another support member distinct from the support member at the respective second end of the cable.
 26. The method of claim 21, further comprising: rotating the solar energy member about the first axis to adjust azimuth of the solar energy member without touching the plurality of cables such that the solar rays incident on a reflective surface of the solar energy member are reflected toward a solar energy receiver; and rotating the solar energy support member about the second axis to adjust elevation of the solar energy member without touching the plurality of cables such that the solar rays incident on a reflective surface of the solar energy member are reflected toward a solar energy receiver. 